'Does someone have to die?' How neglect left Britain's rivers flooded with sewage

Red kites swoop above Fawley Meadows as Dave Wallace dips a sampling beaker into the deep green water of the River Thames on a late spring day.

- Sandra Laville

A sharp wind blows droplets upstream towards the arches of Henley Bridge, while the river, its path here straight and wide, pulls downstream towards Windsor on its 215-mile odyssey to the North Sea.

Today, blue and white striped marquees line up for the Henley regatta in the water meadows along its banks. After the rowers depart, the swimmers follow. Wallace used to join them, but dark currents beneath the waters have persuaded him to remain on the banks.

"I only began to realise what was being done to our river when I was swimming the last section of the Henley to Marlow marathon two years ago," Wallace says. "It was a really dry summer, there was barely any flow in the river. As I swam down to the outskirts of Marlow, I could see brown stuff in the water. I realised I was swimming in crap."

Shocked by his awakening, Wallace abandoned his swimming hobby to investigate instead the impact on the river of a toxic cocktail of pollution from treated and untreated sewage, amid growing evidence it is affecting biodiversity and presenting a threat to public health.

He has since uncovered details of all the sewage outflows going into the Thames at Henley, set up regular monitoring of the waters to generate data as evidence, and become a committed river activist.

Wallace is not alone. All along the course of the river, concern for the health of the Thames has led many other people who live, work or play on the water to take up the fight for its health. The past 15 years suggest they have much to do.

In 2009, a year before the Conservatives first took power in a coalition with the Liberal Democrats, a quarter of English rivers were judged as being of good ecological standard; by 2022 not one river was in a healthy state.